You should totally play Splinter!

Flooremoji: Thanks for commenting! I had Splinter in my original list, and casting it was so, so satisfying, but there were so many times I never got to cast it. I think it is worth dropping a Manamorphose for at least one though!

Another good option: Trygon Predator

After doing a bunch of playtests where I tried to Jeskai as well, I concluded that the deck is a lot more solid as predominantly Izzet, with a tiny splash of green just because Ancient Grudge is ridiculous.

Also decided on a transformative sideboard, and brought in the Saheeli Rai infinite mill and infinite damage combos. Normally decks pulling off this combo just shoehorn the Liquimetal Coating in and try to stall until they get their combo out. With mine I can actually use the Coating while I wait, and Argent Mutation can also get the combo started.

Going Izzet also allows me to drop a few lands and add Field of Ruin for even more land control.

I am very happy with how the deck is progressing, and hope to have it in a solid enough place soon to buy it and take it to FNM!

Fair enough, you know your deck!

Dropping 2x Argent Mutation, and trying to pick between these options:

2x Sculpting Steel - Copy any permanent with the help of Coating.

2x Myr Landshaper - More opportunities for land destruction.

2x Spellskite - Great chump blocker, and can protect combo pieces or even me.

2x Bedlam Reveler - Little more end game insurance.

2x Isochron sceptar - Lots of copyable effects

2x (Counterspell/Draw/Control/Removal?)

Any thoughts?

Could you please explain the infinite combo a little better? I don't easily see it.

Sure thing!

So the best starting hand possible for it would be:

Island/Island/Mountain/Altar of the Brood/Liquimetal Coating/Saheeli Rai/Whatever

T1: Land + Altar

T2: Land + Liquimetal

T3: Land + Saheeli

Step 1: Target Saheeli with the Liquimetal.

Step 2: Use Saheeli's -2 ability, targetting herself. She makes a copy of herself that is an artifact in addition to it's other types.

Step 3: When that new Saheeli comes into play it triggers Altar, causing the opponent to mill 1.

Step 4: You now have two Saheeli's and have to sacrifice one due to the Legend rule, so you sacrifice the old one.

Step 5: Since the new Saheeli is already an artifact, Liquimetal being tapped already doesn't matter, so you target her with her own ability again.

Step 6: Repeat Steps 2-5 infinite times.

Step 7: Pass the turn. When the opponent goes to draw and are out of cards in their library, they automatically lose.

You can replace Altar with Reckless Fireweaver for infinite damage, although it will take an extra turn to set up, although they die instantly. You can replace Liquimetal Coating with Argent Mutation, but that will also take an extra turn to set up.

Unless you are constantly drawing Islands, I would suggest you to not run Cryptic Command, as you won't be able to cast is easily and consistently.

Testing at 18 lands to see where the sweet spot is. 20 is definitely plenty for the amount of cantrips and digging the deck has. As long as the deck can run 18 without mulliganning too aggressively then I just opened up space for 2 more spells!

Yugginaut: No worries! It's a weird combo. I'll remove the comments.

Lots of changes! This deck just got a little weirder, but it is so fun, and is the strongest it has been so far. Let me know what you think!

Would this deck be good or bad against affinity...

SynergyBuild: I think it definitely has the potential for the Affinity matchup to be in my favor, it's just a matter of tweaking the deck until it is fast enough to respond regularly. There is a lot of balancing left to do, but I think in the end it may end up being one of the better matchups.

All the mainboard artifact destruction is more than they are normally prepared for normally.

Getting out March of the Machines kills quite a few of their spells instantly. The only thing I have to watch out for is animating too many of their 1+ CMC artifacts that they can then swing with, but it has the added bonus of making them creatures, so equipment can no longer be equipped because you can't equip a creature to a creature. At that point Thing in the Ice  ^Flip flipping bounces their entire board.

Vapor Snag is also pretty solid early on, if you time it right.

I think adding Hurkyl's Recall to the SB would be the last bit I would need to really round out the deck. It really hurts affinity, but it also hits so many key artifacts in other decks as well.

Experimenting with Ral Zerek. I'd like one more non-instant thing to tie into the rest of the deck, and all the abilities are relevant. Seems stronger than mainboarding some of the Saheeli's.

+1: Taps down chump blockers for Thing in the Ice  ^Flip, untaps Isochron Scepter/Liquimetal Coating/Izzet Staticaster or land, as well as untaps attackers if done during second main.

-2: Having another bolt is great, especially being able to do it twice in a row without having to use a turn to tick up first.

-7: Getting more turns is awesome. Even if I have no creatures on the field, being able to spend a few turns just tapping a Liquimetal Coating with March of the Machines in play is brutal. A few free turns to proc Young Pyromancer or flip Thing in the Ice  ^Flip? Yes please.

Let me know your thoughts!

I feel like your mana base is super greedy. First off, I don't think 18 lands is enough to reliably be able to cast 4 drops, especially because you don't have any way to dig deeper for the lands you need outside of Izzet Charm. I also think that 3 Field of Ruin in your deck with 8 cards that require only colored mana is going to cause a lot of cards to be stuck in your hand throughout games.

All the bounce all doesn't seem that great to me. I feel like putting Opt or Serum Visions in those slots would help smooth out your draws, and find you better removal. Remand is also probably better than Delay, and also helps you find lands.

Overall, I would probably cut the Field of Ruins for better lands, go up to probably 19 lands, and trade some of the bounce for cantrips, as those are way better at digging you to control pieces, and are much more synergistic with Young Pyromancer and Thing in the Ice  ^Flip. I'm also not crazy about Muddle the Mixture. I understand that it's pretty nice as a utility, and can sometimes counter things, but modern is a format where the most important things happening are happening on turn 3. Taking your turn 3 to tutor leaves your defenses down and likely puts you way too far behind. I get that a lot of these cards are for the Isochron Scepter, but I think for modern you need cards that will be good without it, because if you don't draw it you're stuck with a lot of bad cards in your hand.

You also seem to have a very small set of cards where Liquimetal Coating is actually any good. The 4 Abrade and 2 March of the Machines are your only payoff, and unless you draw March drawing more that 1 copy of Coating is likely useless. March also makes your Coatings very easy to kill. I don't know what to suggest, maybe a mainboard Shattering Spree or something similar.

At the end of the day, it's your deck so take anything I say and do whatever you want with it. Good luck with the deckbuilding and hope even a little bit of this helped.

Logics: Thanks for the thorough comment! Here are my thoughts.

Lands: The landbase has been working out pretty well so far, but I cut a second Sulfur Falls for a 3rd Field of Ruin, and after a bunch of real playtesting last night (the first non-goldfish testing of the deck). I think that was a mistake. The Fields have been working out well as they are also effectively my 7th and 8th fetches as well. The more I cut them though, the stronger Blood Moon gets instead.

As for the number of lands, at 20 lands I was flooding pretty regularly, so I tried 18 and it was much more consistent. 19 is definitely a good place to settle to, as it would improve the mulligans. Also, I went from no cards above 2 CMC, to four cards at 4 for last night's playtesting, so it was a pretty big swing. I think that should be at most two of them, or take that down to cards that are 3 CMC.

Bounce: Boomerang is really strong, especially when used on a land during the opponent's upkeep step. If it is imprinted, they are locked at that number of lands for the rest of the game, unless they can remove the scepter. That being said, I used to run 4x and it was way too many, and I constantly had multiples left in my hand and nothing constructive to use them on, so I cut them back to 2x. I added Vapor Snag to help with creatures, but effectively caused the 4x Boomerang problem again. I think I will at the very least sideboard the Snags, if not cut them altogether. Those slots would be better served by harder control, like you said, Remand or something similar.

Delay: Delay has been working really well on the scepter, and is awesome against counterspells because all of them except Cryptic Command fizzle when they get recast. I think Delay would be even better alongside a stronger counterspell package, not cut to make room for it. That would help the only real negative I see with Delay being creatures you counter having haste when they get re-cast.

Opt/Visions: I agree with you completely, I think my lack of digging is the biggest issue at the moment. The Izzet Charm and Mission Briefing being my only cards is definitely not enough. Between Opt and Visions I would lean more towards Opt, but I am also looking at Faithless Looting, which would let me pitch extra combo pieces that I don't want in hand.

Muddle: I think that is a fair statement, and although I don't want to cut it entirely, I think going down to a 1-of would be better. That way I still get a tutor if I need it, but I make room for a more versatile spell, and I never end up with 2 in my hand, which has really sucked when it happens. The statement about being good without scepter is spot on, and what I am hoping to accomplish with the deck. It needs to be a value engine, but not an integral part.

Coating: This is something I noticed a few times during my playtesting, so you are on the right track. Often enough I had a March of the Machines or a Liquimetal Coating out, but no removal in hand to use. I think a MB Shattering Spree is a great idea.

Again, thanks for the detailed comment. It really helps to get outside perspectives on this.

Let me know what you think of the newest revision!

Experimenting with Precognition Field. I think this could be a really solid top end of my curve, as long as I have the pressure to finish out the game while it is out.

Settled on Crackling Drake for the end game pressure to turn the corner. I tried Bedlam Reveler but, since I'm not a prowess deck, it was often swinging for just 3 or 4, 5 at the most. The Drake is pretty often swinging for 10+ on its first swing(~T5 or 6), so a lot of the time it only needs to swing once to close out the game.

After recent adjustments I am much happier with the counterspell package. Testing out an even split of Mana Leak and Remand, but that may go back to the playset of Remands. I think 1x Logic Knot is perfect for this deck, as the only thing it really "hurts" is Mission Briefing targets, but if I prioritize Delving fetchlands than it is mostly a non-issue.

Boomerang out for Expel from Orazca. This was a hard decision, but I think a better one for the deck as a whole. Getting 10 permanents for City's Blessing isn't that hard, and once you do you can effectively softlock your opponent into the same draws every single turn for if you manage to get it imprinted. I lose the ability to bounce lands, but that was only a marginal benefit, and Boomerang is only better very early game, which makes the harder to swing.

Also going to run Electrostatic Field in place of Young Pyromancer. Field is seeing almost no play in Modern, except in some instances in Storm in place of Thermo-Alchemist. I think it is severely underplayed, especially for a deck that wants to keep the pressure on. It chumps like crazy, can't be bolted, and comes down early. This will especially help against the aggro and burn matchups, as they tend to employ a lot of early threats with Prowess. This will allow me to run more Anger of the Gods in the side, which makes just about all of my rough matchups (Aggro/Burn/Jund/Dredge) better, and it doesn't outright kill any of my creatures except Vendilion Clique.

With that switch, I haven't decided if I want to go up to a playset of Thing in the Ice  ^Flip, or leave it at a 3-3 split. That will take a bunch of playtesting to see what I like more, but I have a feeling it will be the split.